Anticoagulant Flashcards
What is the main outcome of the intrinsic and the extrinsic pathway?
activation of prothrombin to thrombin
What does 5HT cause at sight of wound? TXA2? ADP?
- vasoconstriction 2. platelet activation 3. Allows clumping
What does epithelial cells produce to suppress platelet aggregation?
PGI2
What measures the intrinsic pathway?
PTT
What measures the extrinsic pathway?
PT
What factors does Active Protein C block?
V and VIII
What does TFPI block? Antithrombin?
- Factor VII 2. Thrombin and X
What is the INR equation? What is normal? High? Low?
(PT patient/ PT mean-normal)^ISI [ISI= international sensitivity index issured to manufactured tissue factors] Normal=.9-1.3 High= 4 or 5-->bleeding Low=.5--> clotting
Does arterial thrombosis or venous thrombosis primarily involve platelet deposition?
Arterial does. Venous is mainly fibrin.
What is clopidogrel activated by? prasugrel?
- CYP2C19 2. Hydrolysis (more effective in most people)
What 2 things does platelet IIb/IIIa receptor function as a receptor for?
- FIBRINOGEN AND VITRONECTIN
2. FIBRINOGEN AND VON WILLEBRAND
How is glycoprotein IIb/IIIa inhibitors administered? Heparin?
Parenterally
What factors does Heparin inhibit? by doing what?
IIA, IXa, and Xa By activating antithombin
How many daltons is low molecular weight?
7000
Where must you never administer heparin?
Never administer intramuscularly
What is HIT?
heparin induced thrombocytopenia- systemic hypercoaguable state in patients treated with UFH heparin for 7 days
T or F–high molecular weight heparin binds to platelets with high affinity and low molecular weight binds to ATIII with low affinity?
False– the affinities are opposite but binding is true
What is the saturable mechanism for heparin removal? unsaturable?
- reticuloendothelial system
2. renal excretion
Does protamine reverse the effect of fondaparinux? What chem structures are added to fondaparinux?
- No although it does in an incomplete way to other LMWHs
2. pentasacc. with added methyl groups
What factors is vitamin K needed for?
II, VII, IX, X, C, and S INHIBITS SYNTHESIS NOT DEGRADATION
What is warfarin cleared by?
cleared by liver and kidney
Does warfarin interact with a lot of drugs?
Yes and diets and disease states
is there any definitive evidence supporting the exclusive use of any fibrinolytic agent?
No–all agents induce a lytic state which may lead to bleeding
What takes fibrin to fibrin degradation products?
Plasmin
What thrombolytic has the longest half life? shortest?
- streptokinase
2. TPA
